LAMMPS (17 Apr 2024 - Development - patch_5May2020-18508-g3c0eaf6870-modified)
# ------ 2D Poiseuille flow ------ #

dimension          2
units              lj
atom_style         rheo
boundary           p p p
comm_modify        vel yes

# ------ Create simulation box ------ #

variable           n equal 1.0
variable           cut equal 3.0

region             box block 0 20 -10 10 -0.01 0.01
create_box         2 box
Created orthogonal box = (0 -10 -0.01) to (20 10 0.01)
  2 by 2 by 1 MPI processor grid
lattice            sq ${n}
lattice            sq 1
Lattice spacing in x,y,z = 1 1 1

region             inner   block INF INF -7.5 7.5 INF INF units box
region             walls   block INF INF -7.5 7.5 INF INF units box side out

create_atoms       2 region walls
Created 100 atoms
  using lattice units in orthogonal box = (0 -10 -0.01) to (20 10 0.01)
  create_atoms CPU = 0.000 seconds
create_atoms       1 region inner
Created 300 atoms
  using lattice units in orthogonal box = (0 -10 -0.01) to (20 10 0.01)
  create_atoms CPU = 0.000 seconds

group              fluid type 1
300 atoms in group fluid
group              rig type 2
100 atoms in group rig

displace_atoms     fluid random 0.1 0.1 0 135414 units box
Displacing atoms ...

# ------ Model parameters ------ #

variable           rho0 equal 1.0
variable           cs equal 1.0
variable           mp equal ${rho0}/${n}
variable           mp equal 1/${n}
variable           mp equal 1/1
variable           zeta equal 1.0
variable	       kappa equal 1.0*${rho0}/${mp}
variable	       kappa equal 1.0*1/${mp}
variable	       kappa equal 1.0*1/1
variable           fext equal 1e-4/${n}
variable           fext equal 1e-4/1
variable           dt_max equal  0.1*${cut}/${cs}/3
variable           dt_max equal  0.1*3/${cs}/3
variable           dt_max equal  0.1*3/1/3
variable           Dr equal 0.05*${cut}*${cs}
variable           Dr equal 0.05*3*${cs}
variable           Dr equal 0.05*3*1

variable           eta equal 0.1
variable           gd0 equal 5e-4
variable           npow equal 0.5
variable           K equal 0.001

mass               * ${mp}
mass               * 1
set                group all rheo/rho ${rho0}
set                group all rheo/rho 1
Setting atom values ...
  400 settings made for rheo/rho
set                group all rheo/status 0
Setting atom values ...
  400 settings made for rheo/status
set                group rig rheo/status 1
Setting atom values ...
  100 settings made for rheo/status

timestep           ${dt_max}
timestep           0.1

pair_style         rheo ${cut} artificial/visc ${zeta} rho/damp ${Dr}
pair_style         rheo 3 artificial/visc ${zeta} rho/damp ${Dr}
pair_style         rheo 3 artificial/visc 1 rho/damp ${Dr}
pair_style         rheo 3 artificial/visc 1 rho/damp 0.15
pair_coeff         * *

# ------ Fixes & computes ------ #

fix                1 all rheo ${cut} quintic 0 shift
fix                1 all rheo 3 quintic 0 shift
fix                2 all rheo/viscosity * constant ${eta}
fix                2 all rheo/viscosity * constant 0.1
#fix                2 all rheo/viscosity * power ${eta} ${gd0} ${K} ${npow}
fix                3 all rheo/pressure * linear
fix                4 rig setforce 0.0 0.0 0.0
fix                5 fluid addforce ${fext} 0.0 0.0
fix                5 fluid addforce 0.0001 0.0 0.0
fix                6 all enforce2d

compute            rho all rheo/property/atom rho

# ------ Output & Run ------ #

thermo             200
thermo_style       custom step time ke press

dump               1 all custom 200 atomDump id type x y vx vy fx fy c_rho

run                20000

CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE

Your simulation uses code contributions which should be cited:

- @article{PalermoInPrep,
 journal = {in prep},
 title = {RHEO: A Hybrid Mesh-Free Model Framework for Dynamic Multi-Phase Flows},
 year = {2024},
 author = {Eric T. Palermo and Ki T. Wolf and Joel T. Clemmer and Thomas C. O'Connor},
}

CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE-CITE

Generated 0 of 1 mixed pair_coeff terms from geometric mixing rule
Neighbor list info ...
  update: every = 1 steps, delay = 0 steps, check = yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 3.3
  ghost atom cutoff = 3.3
  binsize = 1.65, bins = 13 13 1
  4 neighbor lists, perpetual/occasional/extra = 4 0 0
  (1) pair rheo, perpetual, half/full from (2)
      attributes: half, newton on
      pair build: halffull/newton
      stencil: none
      bin: none
  (2) compute RHEO/KERNEL, perpetual
      attributes: full, newton on
      pair build: full/bin/atomonly
      stencil: full/bin/2d
      bin: standard
  (3) compute RHEO/GRAD, perpetual, copy from (1)
      attributes: half, newton on
      pair build: copy
      stencil: none
      bin: none
  (4) compute RHEO/VSHIFT, perpetual, copy from (1)
      attributes: half, newton on
      pair build: copy
      stencil: none
      bin: none
Per MPI rank memory allocation (min/avg/max) = 5.693 | 5.693 | 5.693 Mbytes
   Step          Time          KinEng         Press     
         0   0              0              0            
       200   20             1.2220462e-06  3.7383146e-05
       400   40             4.345762e-06   7.5866885e-05
       600   60             8.8559433e-06  0.00011353743
       800   80             1.4370506e-05  0.00015135634
      1000   100            2.0576198e-05  0.00018903722
      1200   120            2.721926e-05   0.00022533997
      1400   140            3.4099653e-05  0.00026016069
      1600   160            4.1064175e-05  0.00029445207
      1800   180            4.8001225e-05  0.00032893763
      2000   200            5.4832849e-05  0.00036402396
      2200   220            6.1508431e-05  0.00039945249
      2400   240            6.8000141e-05  0.00043534411
      2600   260            7.430136e-05   0.00046943441
      2800   280            8.0415328e-05  0.00049807225
      3000   300            8.6335032e-05  0.00051815375
      3200   320            9.2021626e-05  0.00052618224
      3400   340            9.7387936e-05  0.00051877918
      3600   360            0.00010231526  0.00048650828
      3800   380            0.00010676617  0.00044578079
      4000   400            0.00011080098  0.00044777126
      4200   420            0.00011448127  0.00047047629
      4400   440            0.00011787852  0.00050280249
      4600   460            0.00012106805  0.0005397213 
      4800   480            0.00012412056  0.00057885539
      5000   500            0.0001271078   0.00061396896
      5200   520            0.00013006637  0.00063981812
      5400   540            0.00013295039  0.00065094073
      5600   560            0.00013561487  0.00063918847
      5800   580            0.00013791796  0.00059087656
      6000   600            0.00013983422  0.00052171998
      6200   620            0.00014144833  0.00050658002
      6400   640            0.00014286538  0.0005248626 
      6600   660            0.00014417734  0.00055826606
      6800   680            0.00014546931  0.00060063748
      7000   700            0.00014682553  0.00064421411
      7200   720            0.0001482833   0.00068252242
      7400   740            0.00014977996  0.00070671308
      7600   760            0.00015114829  0.00069774026
      7800   780            0.0001522719   0.00064408311
      8000   800            0.00015312897  0.00055977044
      8200   820            0.00015375669  0.0005225573 
      8400   840            0.00015425683  0.00053833691
      8600   860            0.00015471278  0.00057447427
      8800   880            0.0001552059   0.00061980921
      9000   900            0.00015581593  0.0006659836 
      9200   920            0.0001565564   0.00070813532
      9400   940            0.00015733573  0.00073378551
      9600   960            0.00015802107  0.00071560835
      9800   980            0.00015855339  0.00065636189
     10000   1000           0.00015890743  0.0005699855 
     10200   1020           0.00015908095  0.00053138971
     10400   1040           0.00015915523  0.00054790708
     10600   1060           0.00015921254  0.00058899454
     10800   1080           0.00015934193  0.00063964906
     11000   1100           0.00015959891  0.00069241358
     11200   1120           0.0001599636   0.00073734651
     11400   1140           0.00016036526  0.00074477329
     11600   1160           0.00016075471  0.00071047555
     11800   1180           0.00016109516  0.00064173183
     12000   1200           0.00016131524  0.00055500553
     12200   1220           0.00016136366  0.0005290215 
     12400   1240           0.0001613025   0.00055124296
     12600   1260           0.00016123023  0.00059758627
     12800   1280           0.00016123043  0.00065488735
     13000   1300           0.00016132935  0.0007140876 
     13200   1320           0.00016152165  0.00074795629
     13400   1340           0.00016180372  0.00074730778
     13600   1360           0.00016216585  0.00071370995
     13800   1380           0.0001625339   0.00065176323
     14000   1400           0.00016274999  0.00057515371
     14200   1420           0.00016271295  0.00055878258
     14400   1440           0.00016249768  0.00058448193
     14600   1460           0.00016223675  0.00063096229
     14800   1480           0.00016201846  0.00068639548
     15000   1500           0.00016190593  0.00072444357
     15200   1520           0.00016194466  0.00073830636
     15400   1540           0.00016216164  0.00072773256
     15600   1560           0.00016253174  0.00069215481
     15800   1580           0.00016290895  0.00063239408
     16000   1600           0.00016306463  0.00057466273
     16200   1620           0.00016292218  0.00057951567
     16400   1640           0.00016261117  0.00061504156
     16600   1660           0.00016225906  0.00066066637
     16800   1680           0.00016197993  0.00069751908
     17000   1700           0.0001618568   0.00072202303
     17200   1720           0.00016194264  0.00073255034
     17400   1740           0.00016225911  0.0007231031 
     17600   1760           0.00016270465  0.00068931224
     17800   1780           0.00016304053  0.00062934836
     18000   1800           0.00016302624  0.00058060272
     18200   1820           0.00016274847  0.00058859513
     18400   1840           0.00016236893  0.00061804803
     18600   1860           0.00016202777  0.00065393237
     18800   1880           0.0001618184   0.00068747094
     19000   1900           0.0001618044   0.00071352541
     19200   1920           0.00016204402  0.00072351769
     19400   1940           0.00016249999  0.00071330322
     19600   1960           0.00016297924  0.00067984167
     19800   1980           0.00016317435  0.00061634142
     20000   2000           0.00016301186  0.00057234115
Loop time of 15.6198 on 4 procs for 20000 steps with 400 atoms

Performance: 11062881.511 tau/day, 1280.426 timesteps/s, 512.170 katom-step/s
99.7% CPU use with 4 MPI tasks x no OpenMP threads

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 2.1979     | 2.4473     | 2.6992     |  15.7 | 15.67
Neigh   | 0.024709   | 0.027006   | 0.029223   |   1.3 |  0.17
Comm    | 0.4657     | 0.71686    | 0.9662     |  29.0 |  4.59
Output  | 0.033698   | 0.036781   | 0.039359   |   1.1 |  0.24
Modify  | 12.306     | 12.313     | 12.319     |   0.2 | 78.83
Other   |            | 0.07916    |            |       |  0.51

Nlocal:            100 ave         107 max          93 min
Histogram: 1 0 0 1 0 0 1 0 0 1
Nghost:          185.5 ave         192 max         179 min
Histogram: 1 0 0 1 0 0 1 0 0 1
Neighs:           1712 ave        1848 max        1598 min
Histogram: 1 0 1 0 0 1 0 0 0 1
FullNghs:         3424 ave        3682 max        3174 min
Histogram: 1 0 1 0 0 0 1 0 0 1

Total # of neighbors = 13696
Ave neighs/atom = 34.24
Neighbor list builds = 331
Dangerous builds = 0


Total wall time: 0:00:15
